When I realized how precious it was, it was a memory that played so briefly (since I can't see the kanji for kanketsu, I picked the most likely meaning)
I still continue longing for the past Unable to divide the present and past (judging by the rest of the lyrics, I guessed "divide", since the original word means "conclude")

We frolicked on our way home, didn't we One more DATE with my memories
*kyun* (this is a sound effect for a pinching feeling) the days that torment my heart will not fade, they only become prettier

Time goes by It increases daily
Without changing These feelings suffocate me
At all seasons I don't have any memories That don't contain you

The piling up snow Shakes fleetingly And steals away warmth
I just believed it was a thread that would never come loose The transient promise....Liar.

Too high-handed to say "I love you" Why, because I was scared of getting hurt BAMBI
I just want to excessively hold your hand, you who gives excessive love
Act like a (spoiled) child only in front of you, I'm that TYPE Come on, inside a dream it's goodnight TIME
SIZE Together with (odoko? this is a mistransliteration. I don't think it's "otoko", man, either) Until tomorrow morning it's happy TIME

Time goes by Still I am bound
Without changing My feelings overflow
At all seasons I don't need a tomorrow Without you

The piling up snow Shakes fleetingly And steals away warmth
I just believed it was a thread that would never come loose The transient promise disappears...
I love you
Just those three words (I'm assuming "Tatte sou" was a mistransliteration of "tatta sono") Why
Couldn't I use them?
Brashly, I spilled the words
"I don't need this commonplace love"
(My interpretation, the sentence is a bit vague but I think that's what those two lines mean. Also the two lines are swapped around due to Japanese grammar being the opposite of English)

If I could go back just one more time Could I change just a little bit?

Even the endlessly repeating pain and sadness stab lovingly into my heart
I just believed it was a thread that would never come loose The transient promise....Liar.

Those irreplacable days

From the seasons you weren't there, To that season you were
I thank you from the bottom of my heart.

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The title probably refers to the colors of the seasons.
I am assuming it is the singer who couldn't say "I love you", though the lines do not specify.